package util;

/**
 * Created by Arat.Wu on 2017/12/28.
 */
        import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;


public class Alpha {
    public static void main(String[] args) {
        transferAlpha();
    }

    public static byte[] transferAlpha() {

        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        File file = new File("E:/selected.png");
        InputStream is;
        try {
            is = new FileInputStream(file);
        //如果是MultipartFile类型，那么自身也有转换成流的方法：is = file.getInputStream();
            BufferedImage bi=ImageIO.read(is);
            Image image=(Image)bi;
            ImageIcon imageIcon = new ImageIcon(image);
            BufferedImage bufferedImage = new BufferedImage(imageIcon
                    .getIconWidth(), imageIcon.getIconHeight(),
                    BufferedImage.TYPE_4BYTE_ABGR);
            Graphics2D g2D = (Graphics2D) bufferedImage.getGraphics();
            g2D.drawImage(imageIcon.getImage(), 0, 0, imageIcon
                    .getImageObserver());
            int alpha = 0;
            for (int j1 = bufferedImage.getMinY(); j1 < bufferedImage
                    .getHeight(); j1++) {
                for (int j2 = bufferedImage.getMinX(); j2 < bufferedImage
                        .getWidth(); j2++) {
                    int rgb = bufferedImage.getRGB(j2, j1);

                    int R =(rgb & 0xff0000 ) >> 16 ;
                    int G= (rgb & 0xff00 ) >> 8 ;
                    int B= (rgb & 0xff );
                    if(((255-R)<30) && ((255-G)<30) && ((255-B)<30)){
                        rgb = ((alpha + 1) << 24) | (rgb & 0x00ffffff);
                    }

                    bufferedImage.setRGB(j2, j1, rgb);

                }
            }

            g2D.drawImage(bufferedImage, 0, 0, imageIcon.getImageObserver());
            ImageIO.write(bufferedImage, "png", new File("e:/67.png"));//直接输出文件

            // ImageIO.write(bufferedImage, "png", byteArrayOutputStream);//转换成byte数组
        } catch (Exception e) {
            e.printStackTrace();
        }finally{

        }
        return byteArrayOutputStream.toByteArray();
    }
}
